1. Field of the Invention
The present invention relates to an image capturing apparatus, a method of controlling the same, and a storage medium.
2. Description of the Related Art
Some image capturing apparatuses such as digital video cameras and digital still cameras have a so-called macro image capturing function of allowing to select a normal image capturing mode or a macro image capturing mode. Such an image capturing apparatus causes the user (operator) to estimate the distance to the object by eye and select one of the image capturing modes via a selector button or the like. When the user selects the macro image capturing mode, the distance up to the object (that is, the distance between the image capturing apparatus and the object) is short. Hence, control unique to the macro image capturing mode is performed by, for example, making the light emission amount of the electronic flash smaller than that in the normal image capturing mode.
Leaving selection of the normal image capturing mode or macro image capturing mode to the user in the image capturing apparatus having the macro image capturing function lowers the convenience for the user (usability). Additionally, the user may forget to select the macro image capturing mode when the object is nearby.
Japanese Patent Laid-Open No. 2007-225713 has proposed a technique of automatically selecting the normal image capturing mode or macro image capturing mode based on an AF evaluation value (focus signal) representing the sharpness (contrast) of an image signal or the position of the focusing lens (focus lens). In Japanese Patent Laid-Open No. 2007-225713, it is determined in the normal image capturing mode that the object exists in the macro region (closest side) when the AF evaluation value obtained by moving the focusing lens in the optical axis direction is smaller than a predetermined reference value, or when the AF evaluation value has its peak on the side where an object in the short range is brought into focus.
However, if it is determined based on only the AF evaluation value or the position of the focusing lens whether the object exists in the macro region, as in Japanese Patent Laid-Open No. 2007-225713, a determination error may occur.
More specifically, if the AF evaluation value changes due to an abrupt change in brightness, for example, if the AF evaluation value increases when the driving direction of the focusing lens is the closest direction, the object is erroneously determined to be on the closest side even if it is not present there. When capturing a low-contrast object or an object in a dark place, the AF evaluation value moderately changes. For this reason, the AF evaluation value larger than the predetermined reference value cannot be obtained, and a determination error occurs. Note that the determination error can be prevented by determining based on the position of the focusing lens in the in-focus state (that is, the stop position of the focusing lens) whether the object exists in the macro region. In this case, however, the determination needs to wait for the stop of the focusing lens. Hence, determining whether the object exists in the macro region takes a long time.